1. Technical Field
The present disclosure relates to a touch panel based on carbon nanotubes.
2. Description of Related Art
Liquid crystal displays (LCDs) are typically used as the display in various devices such as computers, and vehicle and airplane instrumentation. Following the advancement in recent years of various electronic apparatuses toward high performance and diversification, there has been continuous growth in the number of electronic apparatuses equipped with optically transparent touch panels at the front of their respective display devices (e.g., liquid crystal panels). Users may operate a touch panel by pressing or touching the touch panel with a finger, a pen, a stylus, or a like tool while visually observing the liquid crystal display through the touch panel. Therefore, a demand exists for touch panels that are superior in visibility and reliable in operation.
At present, different types of touch panels, including resistance, capacitance, infrared, and surface sound-wave types have been developed. Resistance-type touch panels have been widely used due to their high accuracy and low cost of production.
A conventional resistance-type touch panel includes an upper substrate, a transparent upper conductive layer formed on a lower surface of the upper substrate, a lower substrate, a transparent lower conductive layer formed on an upper surface of the lower substrate, and sometimes, a plurality of dot spacers formed between the transparent upper conductive layer and the transparent lower conductive layer. The transparent upper conductive layer and the transparent lower conductive layer are formed of electrically conductive indium tin oxide (ITO).
In operation, an upper surface of the upper substrate is pressed with a finger, a pen, or a like tool, and visual observation of a screen on the liquid crystal display device provided on a back side of the touch panel is provided. This causes the upper substrate to be deformed, and the upper conductive layer thus comes in contact with the lower conductive layer at the position where the pressing occurs. An electronic circuit separately applies voltages to the transparent upper conductive layer and the transparent lower conductive layer. Thus, the electronic circuit can detect the deformed position.
Each of the transparent conductive layers (e.g., ITO layers) is generally formed by means of ion-beam sputtering, and this method is relatively complicated. Additionally, the ITO layer has poor wearability/durability, low chemical endurance, and uneven resistance over an entire area of the touch panel. All the above-mentioned problems of the ITO layer make for a touch panel and a liquid crystal display screen with low sensitivity and short lifetime.
What is needed, therefore, is to provide a touch panel in which the above problems are eliminated or at least alleviated.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate at least one exemplary embodiment of the present touch panel, the liquid crystal display screen using the same, and the methods for making the touch panel and the liquid crystal display screen incorporating the same, in at least one form, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner.